import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 验证是否已经登录
 */

@WebFilter(filterName="RequireFilter")
public class RequireFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
        String token = ((HttpServletRequest) req).getParameter("token");
        if (token == null || "".equals(token))
            ((HttpServletResponse) resp).sendRedirect("https://cas.dgut.edu.cn?appid=javaee&state=STATE");

        chain.doFilter(req,resp);
    }

    public void init(FilterConfig config) throws ServletException {

    }

}
